Split grenade



Jan. 8, 1963 H. R. KOLLMEYER ETAL 3,072,056

SPLIT GRENADE Filed Dec. 5, 1955 5 SheetsSheet 1 A3 rig 4h. 22 F2 INVENTOR Herman R. Ko/lme yer Jacob Rab/now BY /4 w 5. M, Q. .41. a W QQ ATTORNEYS Jan. 8, 1963 H. R. KOLLMEYER IAITAL 3,072,056

SPLIT GRENADE 3 Sheets-Sheet 2 Filed Dec. 5, 1955 II Ill/l R my mp V NM n K R0 R b m0 w HJ BY w 5. WW (MAJ-$9M ATTORNEYS Jan. 8, 1963 H. R. KQLLMEYER ET AL 3,072,056

SPLIT GRENADE IN VENTOR Herman R. Kol/meyer Jacob Rab/now W. 6%, aw. w m1 QQMVL ATTORNEYS.

United States Patent F 3,072,056 SPLIT GRENADE Herman R. Kollmeyer and Jacob Rabinow, Washington,

D.C., assignors to the United States of America as represented by the Secretary of the Army Filed Dec. 5, 1955, Ser. No. 551,181 1 Claim. (Cl. 102-64) (Granted under Title 35, US. Code (1952), sec. 266) The invention described herein may be manufactured by or for the Government for governmental purposes without the payment to me of any royalty thereon.

This invention relates to explosive ordnance devices and more particularly to grenades.

In general, known grenades are fuzed to explode at a predetermined time after being thrown. A disadvantage of such time fuzed grenades is that the enemy may occasionally be able to pick up a thrown grenade and throw it back at the original thrower.

Grenades fuzed to explode on impact have obvious advantages. An impact fuze for a grenade is disclosed and claimed in the copending US. patent application of Herman R. Kollmeyer, Serial No. 472,540, filed December 1, 1954, now U.S. Patent No. 2,991,717.

For actuation, an impact fuze of the type described in the above-identified Kollmeyer application must be subjected to a force having a substantially component in a particular direction with respect to the body of the fuze. When such a fuze is incorporated in a grenade, means must be provided for insuring that the fuze Will be actuated by grenade impact, regardless of the orientation of the grenade at the time of impact.

The present invention provides a grenade construction that insures the application of force in the necessary direction to an impact fuze of the above-described type, in response to impact from any direction. In a preferred embodiment, the fuze is mounted between two hemispheres, the hemispheres being fitted inside the outer shell of the grenade and being normally slightly separated by a spring. Impact in any direction tends to force the hemispheres together and to actuate the fuze.

' One object of this invention is a grenade the mass of which is employed to actuate the grenade fuze on impact. Another object is a grenade utilizing the centrifugal forces acting on the grenade as it spins through the air to help prevent the functioning of the fuze prior to impact.

An additional object is a grenade which functions upon impact from any direction.

The specific nature of the invention as well as other objects and advantages thereof will clearly appear from the following description and the accompanying drawing, wherein: I I

FIGURE lis a polar section illustrating design of a grenade.

FIG. 2 is similar to FIG. 1 but shows the changed position of the elements after impact.

FIGURE 3 is a perspective view of a grenade with its release linkage in the unreleased'position.

FIGURE 4 is a polar sectional view of the grenade shown in FIG. 3.

FIGURE 5 is a polar sectional-view of the grenade with its release linkage in a released position.

FIGURE 6 is a polar sectional view of the grenade at the time of a polar impact. a

FIGURE 7 is a polar sectional view of the grenade at the time of an equatorial impact.

FIGURE 8 is a polar section of a modified form of the invention.

FIGURE 9 is a polar section of another modified form.

Referring to FIG. 1, numeral 1 indicates the thin outer shell of the grenade which is originally fabricated in two halves, approximating hemispheres, and crimped together the geometric ice at 10 (FIGS. 3-7). Shell 1 is formed with dimples 2a and 2b at opposite poles of the grenade. Side walls 20 and 2d of dimples 2a and 2b form earns, the function of which is explained hereinafter. The inner shells 3a and 3b, substantially hemispherical, have the effect of forming two grenade sections when diameter sections 4a and 4b abut each other as shown in FIG. 2. Fuze well 5, formed partially from recess 6a provided in diameter section 4a and partially from recess 617 formed in diameter section 4b, contains the grenade fuze 7 (FIG. 4).

The outer shell 1 is constructed using four centers indicated by reference characters C1, C2, C3, and C4. With the centers C1 and C2 and an appropriate radius, a top polar arc A1 and a bottom polar arc A2 are struck. In the grenade these are spherical segments. In like manner using the centers C3 and C4 and the same radius as before, a right equatorial arc A3 and a left equatorial arc A4 are struck. In the grenade this is a toric segment. The arcs are joined by straight lines or flats indicated by the reference characters F1, F2, F3, and F4, each line connecting a pair of adjacent arcs, the lines being drawn tangent to the arcs. In the grenade these are conic frustums. The purpose of this construction is described hereinafter.

Disregarding the dimples 8a and 8b in grenade sections 3a and 3b, FIG. 2, the two sections, when in abutting positions as shown, form a hollow sphere, the center of which is indicated by the reference character C4 and the radius of which is that used in the construction of the outer shell foreshortened by an amount equal to the thickness of outer shell 1.

Referring now to FIG. 4, numeral 9 indicates the pair of heavy metal linears positioned inwardly of shells 3a and 3b; these liners break up into lethal fragments when the grenade explodes. The high explosive charge of the grenade is indicated by numeral 10. Within fuze well 5 is located fuze 7 comprising an explosive detonator 12, a stabber 13, a mechanical clock (not shown) to maintain the detonator out of alignment with said stabber prior to fuze arming and to move the detonator into alignment with the stabber at the time of fuze arming (see copend ing application, spura), and a spring 13s biasing the stabber upwardly. away from said detonator.

Before the grenade is to be thrown, the two diameter sections 4a and 4b are maintained in abutting positions as shown in FIG. 4 by a release linkage 14. The linkage comprises a peg 15, the shank 16 of which extends through perforation 17 in shell 1. The shank 16 presses the hemispheres 3a and 3b together. A first lever 18 is pivoted at hook 19, anchored to shell 1, and bears against peg 15. A second lever 20 is pivoted at hook 21, anchored to shell 1. and bears against lever 18. Safety pull pin 22 is normally inserted through eye 23, which is anchored to shell 1, and through perforation 24 in lever 20, in order to maintain peg 15 hearing against grenade section 311 to maintain the two grenade sections in abutting positions and prevent premature arming of the fuze.

It can be seen by an examination of FIG. 4 that stabber 13 extends beyond the upper portion of detonator 12 when the two fuze sections are in abutting positions. It is apparent that stabber 13 and detonator 12 cannot align so long as the two grenade sections are in abutting positions.

A soldier, before he throws the grenade, extracts and discards the safety pull pin 22. The two grenade sections do not separate because he applies pressure with his fingers to release linkage 14. The advantage of the double lever release linkage is that the soldier is allowed to relax his fingers by a considerable amount and yet the sections do not separate sufficiently to permit the fuze to arm. After he throws the grenade, a spring 13s separates the grenade sections, the peg 15 no longer forcing the sections into abutting positions, and a detonator arming means (not shown) moves detonator 12 to a position in alignment with stabber 13 as seen in FIG. 5. The fuze 7 is now in the armed condition. As the grenade spins through the air, centrifugal force helps maintain the separation of the sections.

FIG. 5 shows that when the grenade is armed, fuze body 7 engaging recesses 6a, 6b limits relative movement between hemispherical sections 3a, 3b only in a direction perpendicular to that of diameter sections 4a, 4b. Regardless of the direction of impact, therefore, sections 3a, 315 will accurately move together to form the grenade with diameter sections 4a, 4b in substantially complete abutment as shown in FIG. 7.

If one of the polar areas (the areas near dimples 2a and 2b) of the thrown grenade impacts against a resistant target, the following sequence of events will occur (see FIG. 6): The momentum of the grenade section 3a, overcoming the force of spring 13s, causes grenade section 3a to move into abutting position with section 3b. Stabber 13 is thus driven into detonator 12 to initiate the fuze and explode the grenade.

Should the area of contact of the grenade be in the area of the grenade waist or equator, the following sequence of events will occur (see FIG. 7): The momentum of the two sections will move them in the direction of the grenade trajectory. As this movement occurs, the flat or frusto-conical portion F3 of shell 1 and the Wall or cam section of dimple 2a form coaxial conic surfaces upon which grenade section 3a slides toward section 3b. Similarly, fiat or frusto-conical portion P2 of shell 1 and wall or cam section 2d of dimple 2b form 45 coaxial conic segments upon which grenade section 311 slides toward section3a. The momentum of the two sections, with their recesses 6a., 6b sliding on the surface of fuze body 7 and thereby guided directly towards each other, is ample to overcome spring 13s, and the sections thus slide into abutting positions, driving stabber 13 into detonator 12 to function the fuze and the grenade.

An analysis of FIG. 1 indicates that should the grenade impact on some area other than the polar or equatorial areas referred to, the combined action of the hemispheres 3a, 3b, sliding on their frusto-conical surfaces, and the sliding engagement between recesses 6a, 6b and fuze body 7, insures that the sections 3a, 3b will close together and form the grenade shown in FIG. 7.

In the modification shown in FIG. 8, substantially hemispherical grenade sections 1 and 80b have equatorial annular projections 81a andSlb. These projections have conic camming surfaces 82a and 82b matching similar conic camming surfaces 34a and 84b of annular band 83. Rings 85a and 85b of band 83 react with plane surfaces 86a and 86b of grenade sections 80a and 80b to retain the grenade section in place at all times. Striker 87 cooperates with detonator 88 to function the grenade. Helical spring'89 biases the grenade sections apart. We prefer it to be of conical form so that upon compression it will occupy a minimum of space. Operation of this modified grenade upon polar impact is obvious. Upon equatorial impact the surfaces 82 and 84 cam the sections together while ring 85 and surface 86 prevent the separation of the sections.

The modification illustrated in FIG. 9 is similar to that of FIG. 8, except that a double camming action is utilized. The grenade sections 80a and 80b have annular projections 90a and 9%. These projections are V-shaped in cross-section and have on the inner sides of the V two camming surfaces each; 91a and 92a on projection 99a, and 91b and 92b on projection 90b. Annular band 94 is C-shaped in cross-section and has cam followers 93a and 93b. Helical spring is placed in a convenient recess to bias sections 80a and 80b apart. Striker 87 and detonator 88 function the grenade when the sections are brought together; this is accomplished by polar impact or by equatorial impact. Upon equatorial impact the followers 93a. and 93b of band 94 act upon cam surfaces 91a and 91b on one side and surfaces 92a and 92b upon the opposite surfaces.

It will be apparent that the embodiments shown are only exemplary and that various modifications can be made in construction and arrangement within the scope of the invention as defined in the appended claim.

We claim:

An improved spherical grenade comprising: an outer spherical shell, two inner hemispherical shell sections positioned so that respective diameter sections are in opposed relationships, an explosive charge in said sections, a frangible metal liner between the shell sections and the explosive charge, said outer spherical shell enclosing said sections and having a diameter substantially larger than the combined diameters of said sections, said outer shell and said sections each being provided with inwardly projecting coaxial Wall portions, said wall portions tapering inwardly to form fru'sto-conical surfaces, the frusto-conical surfaces of said hemispherical sections being proportion'ately'larg'er than the frusto-conical surfaces of said outer shell and therefore capable of sliding upon the frusto-conical surfaces of said outer shell, a recess centrally formed in each hemispherical section and extending perpendicularly from each diameter section outwardly towards said frusto-conical surfaces, a fuze body having portions extending into and slidably engaging with each recess in each hemispherical section, a stabber in one end of said fuze body having its longitudinal axis substantially perpendicular to said diameter sections, a detonator in the other end of said fuze body adapted to be moved into a position where its longitudinal axis aligns with the longitudinal axis of said stabber upon arming of the grenade, a spring within a recess and positioned between the stabber end of said fuze body and one of said sections, said spring contacting said one of said sections and biasing said stabber from said detonator towards said one of said sections, said spring also urging the sections apart so that the frustoconical surfaces of said sections are forced against the frusto-conical surfaces of said outer shell, the combined action of the fuze body guiding the sliding of one section with respect to the other by means of said recesses, and the relative sliding'of frusto-conical portions of the sections upon 'frusto-conical portions of the outer shell, permitting relative movement between sections in a direction towards each other and parallel to the longitudinal axis of the stabber, the defined movement of the sections compressing said spring and pushing the stabber into contact with the detonator.

References Cited in the file of this patent UNITED STATES PATENTS 1,316,367 Knight et al. Sept. 16, 1919 2,100,698 Morner Nov. 30, 1937 2,216,587 Cardini Oct. 1, 1940 2,365,246 Cardini Dec. 19, 1944 FOREIGN PATENTS 106,872 Great Britain June 14, 1917 289,358 Italy Mar. 15, 1930 325,338 Italy Oct. 7, 1932 825,335 France Dec. 8, 1937 1,014,164 France Dec. 13, 1947 

